Table 5.
Frontier molecular HOMO and LUMO orbitals, gap value, and descriptors for the optimized structures of the keto-oxime, keto-hydroxylamine, and hydroxyl-oxime tautomers of molnupiravir, obtained by using the DFT/B3LYP/6-311++G(d,p) method.
| Parameter | Keto-oxime | Keto-hydroxylamine | Hydroxyl-oxime |
|---|---|---|---|
| EHOMO (eV) | −6.36339 | −6.91414 | −5.84691 |
| ELUMO (eV) | −1.43132 | −1.89092 | −1.26370 |
| ΔELUMO−HOMO = ELUMO − EHOMO (eV) | 4.93207 | 5.02322 | 4.58321 |
| Ionization energy, I = −EHOMO (eV) | 6.36339 | 6.91414 | 5.84691 |
| Electron affinity, A = −ELUMO (eV) | 1.43132 | 1.89092 | 1.26370 |
| Electronegativity, χ = (I + A)/2 (eV) | 3.89736 | 4.40253 | 3.55531 |
| Chemical potential, μ = −χ (eV) | −3.89736 | −4.40253 | −3.55531 |
| Global chemical hardness, η = (I − A)/2 (eV) | 2.46604 | 2.51161 | 2.29161 |
| Global chemical softness, S = 1/(2η) (eV−1) | 0.20275 | 0.19908 | 0.21819 |
| Global electrophilicity index, ω = μ2/(2η) (eV) | 3.07972 | 3.85854 | 2.75794 |
| Maximum additional electric charge, ΔNmax = −μ/ƞ | 1.58041 | 1.75287 | 1.55145 |